I. Field of the Invention
This invention relates generally to an acoustic silencer for printers used primarily as computer output devices and in particular to an acoustic silencer with a device having slots for paper ingress and egress which can readily be repositioned for different paper feed locations on a variety of printers.
II. Description of the Prior Art
There are a number of silencers for printers and typewriters. In U.S. Pat. Nos. Waldheim 1,604,541; Dollenmayer et al 3,122,228; Britten 2,164,227; Tyberg 1,647,674; Daniel 1,654,922; and Swartz 4,550,798; a number of silencer devices are taught. Waldheim uses a sound deadening casing made up of a boxlike member which encloses a typewriter framework with a cover or hood to seal the sounds from the operation of the typewriter. The hood is open at the front to provide a sufficient aperture so the machine carriage control levers can be manipulated. Dollenmayer et al uses a sliding door mounted within an enclosure such that the enclosure can be slid over the printing portion of the typewriter to reduce the noise level. Daniel uses a plate mounted on a typewriter over the typewriter keys proper. A second plate is attached to the typewriter movable carriage such that the first plate is overlapped. These two plates cooperate to cover the keys and reduce the noise level. Tyberg uses a casing which will fit over the print and carriage portion of a typewriter and provides a narrow aperture for the printed portion of the paper. A glass plate is provided in front of the casing to permit observation of the characters being typed. Britten uses a casing arranged to be mounted over a paper tape feed to confine the noise to the mechanism. Paper tape is fed from a platen through an exit slot in the casing to reduce the vibration due to the type bars striking the paper. Swartz et al uses an acoustic enclosure which has interconnected sound reducing panels forming a substantially rectangular structure which is configured to house a computer printer. Each side panel as well as the top and bottom have acoustic absorbing material in its construction. A rigid thermoplastic hinged cover is provided for closing the enclosure.
None of these devices addresses the problem of adapting a single acoustical enclosure for use with a variety of different printers which have different vertical locations for the horizontal paper feed slots. An incorrectly located paper feed results in paper jamming and filling the acoustic silencer enclosure.